Folding ladder.



W. E. KNOLLENBERG.

FOLDING LADDER.

APPLICATION FILLED APR. 22, 1911.

1,004,883, I I Patented Oct. 3, 1911.

UNITED STATE PATENT @FFlCF.

WILLIAM E. KNOLLENBERG, OF ST. LOUIS, MISSOURI, ASSIGNOR OF FORTY ON E-I-IUNDREDTHS T0 ADOLPI-I KUR-IZ, OF ST. LOUIS, MISSOURI.

FOLDING LADDER.

mosses.

I Specification of Letters Patent.

Application filed April 22, 1911.

To all whom it may concern:

Be it known that I, WVILLIAM E. KNOLLEN- BERG, a citizen of the UnitedStates, and resident of St. Louis, Missouri, have invented certain newand useful Improvements in Folding Ladders, of which the following is aspecification containing a full, clear, and exact description, referencebeing had to the accompanying drawings, forming a part hereof.

My invention relates to improvements in folding ladders and has for itsobject the construction of a ladder made up of a number of sectionshingedly connected so that they may be foldedin compact form, the endsections being provided with rungs which may be disconnected from one ofthe side members, and the hinges connecting the end sections with themiddle sections arranged to articulate in a direction at right angles tothe direction of articulation of the hinges connecting the middlesections so that all of the side pieces may be folded so as to occupy aminimum of space.

With the above purposes in View my in vention consists in certain novelfeatures of construction and arrangement of parts as will be hereinaftermore fully described, pointed out in the claims and illustrated by theaccompanying drawings, in which- Figure 1 is a front elevation of theladder in a fully extended condition, portions of the side pieces of theupper section being broken away; Fig. 2 is a side elevation of theladder in an extended position; Fig. 3

is a front elevation of the ladder partially folded; Fig. 4: is a sideelevation of the ladder as shown in Fig. 3; Fig. 5 is a front elevationof the ladder in a fully folded condition; Fig. 6 is a side elevation ofthe ladder as shown in Fig. 5, a portion of one of the side pieces beingbroken away to reveal the notch for the latch to hold the ladder againstcollapsing; Fig. 7 is an enlarged, detail, sectional plan taken on theline 77 of Fig. 1; Fig. 8 is an enlarged, detail view of one of thehinge connections between the middle sections of the ladder and thelatch for holding the sections against collapsing; and Fig. 9 is a sideelevation, partly in section, of the hinge connection and the latchillus trated in Fig. 8.

Referring by numerals to the accompanying drawings: 1, 2, 3 and 4designate the side pieces of the two middle sections of the ladder whichare connected by rungs 5 and 6, the sections and rungs being of ordinary ladder construction. The sections 1 and 3 are hingedly connected bymeans of a hinge 7, and the sections 2 and 4 hingedly connected by ahinge 8. These hinges are preferably arranged adjacent the rear edges ofthe side pieces so that when the ladder is extended and in use theabutting ends of the sections will serve as knuckles to preventarticulation of the sections beyond a straight line. Formed in the frontedge of the side piece 3 is a transverse notch 9, and carried by thefront edge of the side piece 1 is a leaf spring 10 having a transverserib 11 arranged to engage in the notch 9 so as to hold the side pieces 1and 3 in alinement with each other and against c0llapsing.

12 designates the side pieces of the lower section of the ladder whichare hingedly se cured to the lower ends of the side pieces 1 and 2 ofthe lowermost middle section by means of the hinges 13 which aresubstantially like the hinges 7 and 8 except that they are positioned atright angles relative the hinges 7 and 8. Hingedly secured to one of theside pieces 12 is a rung 14, at the free end of which there is a hook 15arranged for engagement with a strap 16 carried by the opposite sidepiece 12.

17 designate the uppermost side pieces which are hingedly secured to theupper ends of the side pieces 3 and 4: by means of hinges 18, which areidentical in construction and operation with the hinges 13. One of theside pieces 17 is slotted, the length of the slot being substantiallyequivalent to the spacing apart of the side pieces and is arranged toreceive a rung 19 which is hingedly secured upon a pin 20 extendingthrough the slot. At the free end of the rung 19 there is a hook 21 forengagement with a strap 22 carried by the opposite side piece 17, theside pieces 12 and 17 being channeled above and below the straps 16 and22 so that the straps may be applied directly to the inside face of theside pieces. The rungs 19 are held in place parallel with the side piece17 by the frictional engagement of the hook 21 with the end of the slotopposite the hinged end, and the rung 14; of the lowermost laddersection is held in place parallel with the side piece 12 by means of aspring clip 23.

To fold the ladder the leaf spring 10 is drawn outwardly thus releasingits rib 11 from the notch 9 of the opposite side piece. The two middlesections together with the two end sections are then folded over eachother, as shown in Figs. 3 and 1. The rungs 14 and 19 are released bywithdrawing the hooks 15 and 21 from the straps 16 and 22, the rung letbeing swung to a position where it will be engaged by the clip 22 andthe rung 19 swung to a position where it is held parallel with the sidepiece 17, the side pieces 12 and 17 may then be swung on their hinges,as illustrated in Figs. 5 and 6.

It is to be observed that in Figs. 5 and 6 all of the side pieces arefolded to occupy a minimum of space. Such a ladder may be constructed ofvery light material, may be readily folded or unfolded as required, andoccupies a minimum of space when folded so that it may be readilycarried or transported.

The particular construction of hinges shown is not essential to myinvention, but it is essential that hinges be employed in the positionsshown, the hinges of the uppermost sections arranged to articulate indirections at right angles to the direction of articulation of thehinges connecting the two middle sections.

While I have shown the outer sections as having only one rung each andthe middle sections as having two and three rungs, it is obvious if alarger or longer ladder is desired its side pieces may be made longerand a greater number of rungs employed.

I claim:

1. In a folding ladder, a pair of sections having their side piecesconnected by fixed rungs, hinges connecting said pair of sections, aside piece hingedly connected with the free ends of each of the sidepieces of said pair of sections, the hinges of the last mentioned sidepieces arranged at right angles to the hinges connecting said pair ofsections, and folding rungs connecting said last mentioned side pieces.

2. In a folding ladder, a pair of sections having their side piecesconnected by fixed rungs, hinges connecting said pair of sections, aside piece hingedly connected with the free ends of each of the sidepieces of said pair of sections, the hinges of the last mentioned sidepieces arranged at right angles to the hinges connecting said pair ofsections, folding rungs connecting said last mentioned side pieces, andmeans carried by the hinged end of the pair of sections to prevent theirarticulation in one direction upon their hinges.

In testimony whereof, I have signed my name to this specification, inpresence of two subscribing witnesses.

WVILLIAM E. KNOLLENBERG.

WVitnesses:

E. L. -WALLAcE, N. G. BUTLER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissionerof Patents,

Washington, D. G. i

